1. Field of the Invention
The present invention relates to electrical components, to a method of forming a conductive track on a magnetic record medium and, more particularly, to such a method employing electroless plating.
2. Description Relative to the Prior Art
In order to connect a high density, multi-track recording head to an electronics package, it is necessary to devise a suitable multi-conductor connector device. For example, a bundle of wires may be provided having an end of each wire connected to an individual recording head and the other end connected to a terminal of the electronics package. Alternatively, a printed circuit may be employed which comprises a substrate (flexible or rigid depending upon the application) having a plurality of conductive tracks formed on one or both sides of the circuit board. The recording head and the electronics package are connected to the printed circuit board through short wires. Such circuit boards are generally manufactured using a photolithographic process.
In the case of a high density, multi-track recording head the problem of connecting the head to the electronics package becomes more acute. Consider the manufacture of recording heads having track densities on the order of 500 heads per inch: When it is considered that each individual head may have three or more electrical connections, it becomes apparent that prior art methods of connecting recording heads to an electronics package are unsatisfactory. If wire connections are used, for example, space requirements coupled with the extremely large number of electrical connections necessitates the use of extremely fine wires. In a bundle of 500 or more thin and fragile wires, breakage of some is almost unavoidable unless great care is taken to handle the wires delicately. The use of printed circuit boards may appear to avoid this problem somewhat because the conductive tracks are formed on a relatively durable substrate. The problem with printed circuit boards, however, is that conductive tracks can only be formed at a density less than about 250 tracks per inch, even assuming that conductive tracks are formed on both sides of the printed circuit board. The problem thus remains of how to connect a high density, multi-track record head to an electronics package.
U.S. Pat. Nos. 3,633,189 and 3,805,213 disclose connector devices for electrically connecting a multi-track magnetic record head to an electronics package. Each of these patents discloses a cable structure comprising a substrate of nonconductive material having a large number of conductive tracks formed thereon. The substrate is shaped and the conductive tracks are formed in such a manner that the substrate can be folded or bent to permit a larger number of connecting paths to be concentrated within a small area at the end of the cable than would otherwise be possible. It would appear, however, that such cable connectors are not suitable for use with the high density, multi-track record heads discussed above.